Usually I try and stay away from using lengthy excerpts in a blog, but in this case I found that there is so little information about this Herb, that I decided to pass on this wonderful and in depth information from mdidea.com:

Willow Herb ExtractEpilobium angustifolium extract got derived from a plant commonly known as fireweed or willow herb. Can have antimicrobial and anti-irritant properties for skin. Epilobium angustifolium L. is a circumpolar member of the evening-primrose family (Onagraceae). The plant is an abundant perennial that dominates many plant communities undergoing succession, quickly reclaiming disturbed ground such as cut or burned forest, thus explaining its common name, fireweed. It is also commonly known as rosebay willowherb and great willowherb.

Although sometimes considered a weed, it has a long history of use as both a food and a medicinal.

Historically, medicinal use includes oral use of the plant extracts, often in the form of an infusion or tea, as a treatment for prostate and urinary problems including benign prostatic hyperplasia (BPH) or enlarged prostate; and for various gastrointestinal disorders such as dysentery or diarrhea. Topically the plant has been used traditionally as a soothing, cleansing and healing agent to treat minor burns, skin rashes, ulcers, and numerous other skin irritations and afflictions.

The most tangible commercial applications of Epilobium angustifolium to date appear to be those related to the topical use of the extracts for their potent anti-irritant, anti-inflammatory, and free radical-scavenging effects. Since time immemorial, the peoples of the forest regions of Canada have used the juices of Willowherb(Epilobium angustifolium) as skin cleansers, fresheners and soothers for irritated areas of the skin. There are abundant ethnobotanical anecdotes concerning the beneficial effects of this substance on irritated skin.

Commercial extracts of the plant are widely used in cosmeceuticals and personal care products ranging from creams, lotions, and shampoos to hair tonics and baby wipes. Therapeutic products for various skin conditions such as those for eczema, psoriasis, seborrhea, fungal infections, and rosacea have incorporated willowherb as a functional active ingredient. The main nutraceutical, cosmetic and therapeutic uses of willowherb and its extracts have, over the past 20 years, received scientific support and are explainable, at least in part, by the unusual chemical make-up of the plant.

Rose Bay Willow-herb Extract(Epilobium angustifolium L) and Oenothein-B play as principle bioactive molecule found in fashionable skin care cosmetics for acne treatment etc. This molecule has been patented for its wide ranging bioactivity including anti-viral, antitumour, and anti-hyperandrogenic applications and has also demonstrated free radical scavenging ability. Rose Bay Willow-herb Extract(Epilobium angustifolium L) extract has also been shown to effectively kill the P. Acne bacterium associated with acne.

Epilobium angustifolium (Rose Bay Willow-herb,Fireweed) contains a bioactive molecule: Oenothein-B, patented for its wide ranging anti-inflammatory, non-steroidal activity. Its antiviral, anti-tumor and free radical scavenging properties soothe inflamed or irritated skin while allowing healing to take place. The potent bioactivity makes it a therapeutic product recommended for irritated, red skin. Research performed in North America and Europe has found it outperforms 1% hydrocortisone in results measured: _ hour, 1 hour, 4 hours, and 24 hours. The Willowherb lotion was especially effective during the first three measured points of the test, the time that is most important to the healing process.

Cosmetic Property:Epilobium Angustifolium Extract is commonly known as Willowherb Extract,this extract is extracted from the Flower Leaf Stem part of this plant,and it got named as canadian willow herb in north america, general property of this extracts effective against acne bacteria, anti-inflammatory, anti-irritant, antioxidant, anti-microbial, anti-viral, cleansing. Acts as a natural analgesic, mimics hydrocortisone to sooth discomfort.

Thus this ingredient is excellent for traumatized skin whether by injury or cosmetic medical procedures. Epilobium augustifolium (Rose Bay Willow-herb), contains a bioactive molecule: Oenothein-B, patented for its wide ranging anti-inflammatory, non-steroidal activity. Its antiviral, anti-tumor and free radical scavenging abilities soothe inflamed or irritated skin while allowing healing to take place. The potent bioactivity makes it a therapeutic product recommended for irritated, red skin. Research performed in North America and Europe has found it outperforms 1% hydrocortisone in results measured: _ hour, 1 hour, 4 hours, and 24 hours. The Willowherb lotion was especially effective during the first three measured points of the test, the time that is most important to the healing process. Thus this ingredient is excellent for traumatized skin whether by injury or cosmetic medical procedures.

Since time immemorial, the peoples of the forest regions have used the juices of Willowherb(Epilobium angustifolium) as skin cleansers, fresheners and soothers for irritated areas of the skin. There are abundant ethnobotanical anecdotes concerning the beneficial effects of this substance on irritated skin. Contrary to what the name might imply, Willowherb is a non-willow plant that "soothes the forest" by quickly reclaiming areas scorched by forest fires. Ethnobotanical reports reveal that traditional healers used extracts of this plant to "soothe the human forest" as well. Clinical research has recently verified these reports further characterizing the potent non-steroidal anti-inflammatory activity of this extract and its component.

The principle bioactive molecule found in Willowherb extract is Oenothein-B. This molecule has been patented for its wide ranging bioactivity including anti-viral, antitumour, and anti-hyperandrogenic applications and also has demonstrated free radical scavenging ability.Willowherb has also been shown to effectively kill the P. Acne bacterium associated with acne.

The potent and wide ranging bioactivity of our Willowherb make them a vital component of almost any natural therapeutic product. Willowherb extracts provide safe, natural plant-derived functionality as strong as that of the best over-the-counter anti-irritants and anti-inflammatory products available. Action is exceptionally fast and the extracts are highly potent, so that high-efficiency formulated products are readily obtainable even with low levels of ingredient.